21010123200 has 672 divisors, whose sum is σ = 80821255680. Its totient is φ = 4721868800.

The previous prime is 21010123163. The next prime is 21010123213. The reversal of 21010123200 is 232101012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 79886269 + ... + 79886531.

Almost surely, 2^21010123200 is an apocalyptic number.

21010123200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21010123200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40410627840).

21010123200 is an abundant number, since it is smaller than the sum of its proper divisors (59811132480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21010123200 is a wasteful number, since it uses less digits than its factorization.

21010123200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21010123200 its reverse (232101012), we get a palindrome (21242224212).

The spelling of 21010123200 in words is "twenty-one billion, ten million, one hundred twenty-three thousand, two hundred".